Since their discovery, the mitomycins (cf: mitomycin C) have engaged the interest of chemists, biologists, and oncologists.'Considerable excitement was generated by the discovery of novel structures related to the mitomycins at the level of structure and mechanism of action. 2 From a chemical standpoint, the most intriguing of these is FR- 900482 (l), which is isolated from Streptomyces sandaensis No. 6897.3 Not surprisingly, ...